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Abstract The mechanical function of the myocardium is defined by cardiomyocyte contractility and the biomechanics of the extracellular matrix (ECM). Understanding this relationship remains an important unmet challenge due to limitations in existing approaches for engineering myocardial tissue. Here, they established arrays of cardiac microtissues with tunable mechanics and architecture by integrating ECM‐mimetic synthetic, fiber matrices, and induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs), enabling real‐time contractility readouts, in‐depth structural assessment, and tissue‐specific computational modeling. They found that the stiffness and alignment of matrix fibers distinctly affect the structural development and contractile function of pure iPSC‐CM tissues. Further examination into the impact of fibrous matrix stiffness enabled by computational models and quantitative immunofluorescence implicates cell‐ECM interactions in myofibril assembly, myofibril maturation, and notably costamere assembly, which correlates with improved contractile function of tissues. These results highlight how iPSC‐CM tissue models with controllable architecture and mechanics can elucidate mechanisms of tissue maturation and disease.
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Microenvironmental determinants of organized iPSC-cardiomyocyte tissues on synthetic fibrous matrices
Cardiomyocytes derived from induced pluripotent stem cells (iPSC-CMs) show great potential for engineering myocardium to study cardiac disease and create regenerative therapies. However, iPSC-CMs typically possess a late embryonic stage phenotype, with cells failing to exhibit markers of mature adult tissue. This is due in part to insufficient knowledge and control of microenvironmental cues required to facilitate the organization and maturation of iPSC-CMs. Here, we employed a cell-adhesive, mechanically tunable synthetic fibrous extracellular matrix (ECM) consisting of electrospun dextran vinyl sulfone (DVS) fibers and examined how biochemical, architectural, and mechanical properties of the ECM impact iPSC-CM tissue assembly and subsequent function. Exploring a multidimensional parameter space spanning cell-adhesive ligand, seeding density, fiber alignment, and stiffness, we found that fibronectin-functionalized DVS matrices composed of highly aligned fibers with low stiffness optimally promoted the organization of functional iPSC-CM tissues. Tissues generated on these matrices demonstrated improved calcium handling and increased end-to-end localization of N-cadherin as compared to micropatterned fibronectin lines or fibronectin-coated glass. Furthermore, DVS matrices supported long-term culture (45 days) of iPSC-CMs; N-cadherin end-to-end localization and connexin43 expression both increased as a function of time in culture. In sum, these findings demonstrate the importance of recapitulating the fibrous myocardial ECM in engineering structurally organized and functional iPSC-CM tissues.
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- Award ID(s):
- 1647837
- PAR ID:
- 10252607
- Date Published:
- Journal Name:
- Biomaterials Science
- Volume:
- 9
- Issue:
- 1
- ISSN:
- 2047-4830
- Page Range / eLocation ID:
- 93 to 107
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0BM01247E
